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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Fri, 23 Apr 2021 18:53:58 +0300
Message-ID: <CAHp75VfCbbnN-TBJiYFb=6Rhf30jA-Hz1p1UORsubF7UG6-ATw@mail.gmail.com>
Subject: Re: [PATCH v6 3/3] pinctrl: Add Xilinx ZynqMP pinctrl driver support
To:     Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
Cc:     Linus Walleij <linus.walleij@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Michal Simek <michal.simek@xilinx.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        devicetree <devicetree@vger.kernel.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        git <git@xilinx.com>, saikrishna12468@gmail.com
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On Thu, Apr 22, 2021 at 11:31 AM Sai Krishna Potthuri
<lakshmi.sai.krishna.potthuri@xilinx.com> wrote:
>
> Adding pinctrl driver for Xilinx ZynqMP platform.
> This driver queries pin information from firmware and registers
> pin control accordingly.
>
> Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>

You may reduce the number of LOCs by joining some lines. See below.

...

> +config PINCTRL_ZYNQMP
> +       tristate "Pinctrl driver for Xilinx ZynqMP"
> +       depends on ZYNQMP_FIRMWARE
> +       select PINMUX
> +       select GENERIC_PINCONF
> +       default ZYNQMP_FIRMWARE
> +       help
> +         This selects the pinctrl driver for Xilinx ZynqMP platform.
> +         This driver will query the pin information from the firmware
> +         and allow configuring the pins.
> +         Configuration can include the mux function to select on those
> +         pin(s)/group(s), and various pin configuration parameters
> +         such as pull-up, slew rate, etc.

Missed module name.

...

> +/*
> + * ZynqMP pin controller
> + *
> + * Copyright (C) 2020 Xilinx, Inc.

2021?

> + *
> + * Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
> + * Rajan Vaja <rajan.vaja@xilinx.com>
> + */

...

> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/firmware/xlnx-zynqmp.h>

...

> +static int zynqmp_pinconf_cfg_get(struct pinctrl_dev *pctldev,
> +                                 unsigned int pin,
> +                                 unsigned long *config)
> +{
> +       unsigned int arg, param = pinconf_to_config_param(*config);
> +       int ret;

> +       if (pin >= zynqmp_desc.npins)
> +               return -EOPNOTSUPP;

Is it possible?

> +       switch (param) {
> +       case PIN_CONFIG_SLEW_RATE:
> +               param = PM_PINCTRL_CONFIG_SLEW_RATE;
> +               ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
> +               break;
> +       case PIN_CONFIG_BIAS_PULL_UP:
> +               param = PM_PINCTRL_CONFIG_PULL_CTRL;

> +               ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
> +               if (arg != PM_PINCTRL_BIAS_PULL_UP)
> +                       return -EINVAL;

Error code being shadowed. Instead check it here properly.

> +               arg = 1;
> +               break;
> +       case PIN_CONFIG_BIAS_PULL_DOWN:
> +               param = PM_PINCTRL_CONFIG_PULL_CTRL;
> +               ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
> +               if (arg != PM_PINCTRL_BIAS_PULL_DOWN)
> +                       return -EINVAL;

Ditto.

> +               arg = 1;
> +               break;
> +       case PIN_CONFIG_BIAS_DISABLE:
> +               param = PM_PINCTRL_CONFIG_BIAS_STATUS;
> +               ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
> +               if (arg != PM_PINCTRL_BIAS_DISABLE)
> +                       return -EINVAL;

Ditto.

> +               arg = 1;
> +               break;
> +       case PIN_CONFIG_POWER_SOURCE:
> +               param = PM_PINCTRL_CONFIG_VOLTAGE_STATUS;
> +               ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
> +               break;
> +       case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
> +               param = PM_PINCTRL_CONFIG_SCHMITT_CMOS;
> +               ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
> +               break;
> +       case PIN_CONFIG_DRIVE_STRENGTH:
> +               param = PM_PINCTRL_CONFIG_DRIVE_STRENGTH;
> +               ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
> +               switch (arg) {
> +               case PM_PINCTRL_DRIVE_STRENGTH_2MA:
> +                       arg = DRIVE_STRENGTH_2MA;
> +                       break;
> +               case PM_PINCTRL_DRIVE_STRENGTH_4MA:
> +                       arg = DRIVE_STRENGTH_4MA;
> +                       break;
> +               case PM_PINCTRL_DRIVE_STRENGTH_8MA:
> +                       arg = DRIVE_STRENGTH_8MA;
> +                       break;
> +               case PM_PINCTRL_DRIVE_STRENGTH_12MA:
> +                       arg = DRIVE_STRENGTH_12MA;
> +                       break;
> +               default:
> +                       /* Invalid drive strength */
> +                       dev_warn(pctldev->dev,
> +                                "Invalid drive strength for pin %d\n",
> +                                pin);
> +                       return -EINVAL;
> +               }
> +               break;
> +       default:
> +               ret = -EOPNOTSUPP;
> +               break;
> +       }
> +
> +       if (ret)
> +               return ret;
> +
> +       param = pinconf_to_config_param(*config);
> +       *config = pinconf_to_config_packed(param, arg);
> +
> +       return 0;
> +}

...

> +                       ret = -EOPNOTSUPP;

Isn't it ENOTSUP for all cases here?

...

> +       ret = zynqmp_pm_query_data(qdata, payload);
> +       if (ret)
> +               return ret;
> +
> +       *ngroups = payload[1];
> +

> +       return ret;

return 0;

...

> + * Query firmware to get group IDs for each function. Firmware returns
> + * group IDs. Based on group index for the function, group names in

on the group

> + * the function are stored. For example, the first group in "eth0" function
> + * is named as "eth0_0" and second group as "eth0_1" and so on.

and the second

> + *
> + * Based on the group ID received from the firmware, function stores name of
> + * the group for that group ID. For example, if "eth0" first group ID
> + * is x, groups[x] name will be stored as "eth0_0".
> + *
> + * Once done for each function, each function would have its group names
> + * and each groups would also have their names.

each group

...

> +done:
> +       func->groups = fgroups;
> +
> +       return ret;

return 0; ?

...

> +       *nfuncs = payload[1];
> +
> +       return ret;

Ditto.

...

> +       ret = zynqmp_pm_query_data(qdata, payload);
> +       if (ret)
> +               return ret;
> +
> +       memcpy(groups, &payload[1], PINCTRL_GET_PIN_GROUPS_RESP_LEN);
> +
> +       return ret;

Ditto.

...

> + * Query firmware to get groups available for the given pin.
> + * Based on the firmware response(group IDs for the pin), add
> + * pin number to the respective group's pin array.
> + *
> + * Once all pins are queries, each groups would have its number

each group

> + * of pins and pin numbers data.

...

> +       return ret;

return 0;

...

> + * Query number of functions and number of function groups (number
> + * of groups in given function) to allocate required memory buffers

in the given

> + * for functions and groups. Once buffers are allocated to store
> + * functions and groups data, query and store required information
> + * (number of groups and group names for each function, number of
> + * pins and pin numbers for each group).

...

> +       pctrl->funcs = funcs;
> +       pctrl->groups = groups;
> +
> +       return ret;

return 0;

...

> +       *npins = payload[1];
> +
> +       return ret;

Ditto.

...

> +               dev_err(&pdev->dev, "pin desc prepare fail with %d\n",
> +                       ret);

One line.

...

> +               dev_err(&pdev->dev, "function info prepare fail with %d\n",
> +                       ret);

Ditto.

...

> +       pctrl->pctrl = pinctrl_register(&zynqmp_desc, &pdev->dev, pctrl);

devm_pinctrl_register()

> +       if (IS_ERR(pctrl->pctrl))
> +               return PTR_ERR(pctrl->pctrl);

...

> +};

> +

Extra blank line.

> +MODULE_DEVICE_TABLE(of, zynqmp_pinctrl_of_match);

...

> +};

> +

Ditto.

> +module_platform_driver(zynqmp_pinctrl_driver);

-- 
With Best Regards,
Andy Shevchenko